In recent years, one person possesses many cards. The amount of information has been kept increasing since various kinds of information are stored in a card and rewritten as necessary.
The increase in the amount of information is essential in many fields. For example, there are heightened calls for strengthening product safety or management system to the food industry or the manufacturing industry, and thus, product information is increased. However, the current products information is exceedingly little, as information such as a country of manufacture, a maker, a product number which are mainly provided by using bar codes containing figures of over ten columns. Further, when bar codes are used, much time is required due to a manual operation of reading each product.
Considering the above, there is devised a method of managing product using networks. Using this method, the information on products is transferred to stores via a server by inputting identifiers of products with a network terminal in each store (Reference 1: Japanese Patent Laid-Open No. 2002-230141). According to Reference 1, the identifiers of products are shown with two-dimensional bar codes or character strings, and are sent to a server after they are inputted into terminals in stores. The products have a detachable storage medium that holds programs and data on products, or personal information. Cards such as an IC card, a smart card, and a compact flash card are given as examples of the storage medium.
There is proposed a method by which a minute IC chip is installed in valuable securities for preventing misuse thereof, and at the same time, if it returns to a regular manager, the manager can use it again (Reference 2: Japanese Patent Laid-Open No. 2001-260580).